JPH05223693A - Method for measuring dimension of optical connector - Google Patents

Abstract

PURPOSE:To accurately measure the dimension of optical connector by keeping an end face space in the butt direction against a light sending/receiving ferrule to be a space as desired on the basis of the correlation between the end face space and transmission loss. CONSTITUTION:While a Z-axis stage is being shifted vertically, the transmission loss is measured at respective shifting positions to prepare a correlation diagram showing the transmission loss against the end face space. On the other hand, the intensity of light transmitted from a light sending/receiving fiber 8 is measured by an optical power meter. Then a computer calculates an end face interval Z between a multi-core connector 2 and a light sending/receiving ferrule 7 based on the correlation diagram with the reference to the optical signal inputted from the optical power meter, and outputs a correction signal to a Z controller based on the interval Z to correct the stage 12. Furthermore, after the ferrule 7 is changed over, the positions of respective optical fibers 3a and 6 are found out with the computer. Thus a plurality of positions of fiber 3a of the connector 2 can be obtained based on that a pin hole 2c is a reference hole when either is set to the reference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the dimensions of an optical connector.

[0002]

2. Description of the Related Art An optical connector used for butt connection of optical fibers, for example, a multi-core connector, has a plurality of fiber insertion holes formed in a plastic ferrule at a constant arrangement pitch and a positioning guide for butt connection. A multi-core connector having a pin hole through which a pin is inserted, each optical fiber of a multi-core fiber is inserted into each of the plurality of fiber insertion holes, and these are fixed by an adhesive. It is butt-connected with another multi-core connector by fitting it so as to hang it over the pin hole. Here, as the optical connector, there is also a single-core connector in which a single-core fiber is inserted and fixed in a fiber insertion hole of a plastic ferrule.

In such an optical connector, it is necessary to precisely form and process each fiber insertion hole in the order of submicron in order to reduce connection loss due to butt connection with another optical connector as much as possible. Therefore, for the purpose of quality control of the optical connector, dimension measurement is performed to inspect the center position of each fiber insertion hole based on the position of the pin hole in the optical connector.

As a method of measuring the dimensions of such an optical connector, for example, the optical connector and the light-transmitting / receiving ferrule are butted, and the optical fibers attached to both are roughly optically connected. Then, while measuring the light intensity of the measurement light transmitted from either one side, the optical connector is finely moved within a biaxial plane orthogonal to the butting method, and the optical axes of the optical fibers of the optical connector and the sending and receiving ferrule. And the point where the light intensity of the measurement light is maximum is taken as the center of the optical fiber core, that is, the center of the fiber insertion hole in the optical connector.

[0005]

In the above dimension measuring method, however, it is difficult to position the transmitting / receiving ferrule and the optical connector to be measured so that they are in close contact with each other during butt connection. For this reason, at least one of them is allowed to float, and a slight gap of about several μm is formed between them so as to protect the butt end face by slightly retracting them.

However, in the above method, the distance between the end faces is not measured. For this reason, even if the optical axes of the optical fibers of the optical connector and the light-receiving and ferrules are aligned, if the end-face spacing between the light-receiving and ferrule and the measured optical connector is different for each measurement of the optical connector, this difference in end-face spacing will occur. There is a problem in that the transmission loss of the measurement light changes due to the above, and accurate measurement cannot be performed.

The present invention has been made in view of the above points, and when measuring an optical connector, it is possible to maintain a constant distance between the end faces of the transmitting and receiving ferrules and the optical connector that are butt-connected to each other, and the size of the optical connector is high. An object of the present invention is to provide a dimension measuring method of an optical connector that can measure with accuracy.

[0008]

According to the present invention, in order to achieve the above object, a transmitting / receiving ferrule to which an optical fiber is attached and at least one optical fiber are attached, and an optical connector to be measured is butt-connected. Then, in the dimension measuring method of the optical connector, the measuring light transmitted from any one of the transmitting and receiving ferrules or the optical connector is measured on the other side, and the dimension of the optical connector is measured based on the measurement result. The transmission loss is measured while changing the end face spacing in the butting direction when the reference optical connector and the light emitting and receiving ferrules are butted, and the correlation between the end face spacing and the transmission loss is measured in advance, and the correlation is obtained. When measuring the dimensions of the optical connector to be measured based on the relationship, the end face spacing in the abutting direction with the light transmitting / receiving ferrule is desired. It is obtained by a structure for holding the interval.

[0009]

[Function] When the dimension of the optical connector is measured based on the correlation between the end face distance between the light emitting and receiving ferrule and the reference optical connector and the transmission loss, the distance between the light receiving and transmitting ferrule and the optical connector to be measured is kept constant. , The transmission loss caused by other than the end face spacing is eliminated.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to FIGS. FIG. 1 shows the configuration of a dimension measuring system 1 for measuring the dimension of an optical connector according to the method of the present invention. The dimension measuring system 1 includes an XY stage 10 and an X-Y stage 10.
A Y scale 11, a Z stage 12, a Z scale 13, and a computer (ECU) 14 are provided.

The XY stage 10 has a rectangular mounting hole 10a which penetrates in the vertical direction and which positions and mounts the multi-core connector 2 to be measured. This X-
The Y stage 10 can be finely moved in the horizontal direction indicated by arrows X and Y in the drawing together with the attached multi-core connector 2, and the movement in the X and Y directions is controlled by the XY controller 20 shown in FIG.

The multi-core connector 2, as shown in FIG.
One end of a tape fiber 3 obtained by molding a book-shaped optical fiber 3a into a tape shape is attached to the ferrule body 2a. The end face of each optical fiber 3a is exposed at the abutting end face 2b of the front part of the ferrule body 2a. The end surface of each optical fiber 3a is polished. In addition, the multi-core connector 2
Pin holes 2c, 2c are formed on both sides of the ferrule body 2a, and an inspection ferrule 5 is inserted into and removed from each pin hole 2c. Here, the other end of each optical fiber 3a of the tape fiber 3 is connected to a light source 4 (see FIG. 2) using an LED, and each optical fiber 3a has a core with no eccentricity. Further, each optical fiber 3a may be temporarily attached to the fiber insertion hole 2d provided in the ferrule body 2a, or may be adhesively fixed.

The inspection ferrule 5 is used for measurement based on the center position of the pin hole 2c, and is attached to one end of the inspection fiber 6 which is a single-core optical fiber and has an outer shape with no eccentricity. use. The other end of the inspection fiber 6 is connected to the light source 4 shown in FIG. XY scale 1
1 is an X-Y in FIG. 1 to which the multi-core connector 2 is attached.
A laser interference type laser sensor for measuring the fine movement position of the stage 10 in the X and Y directions, and the position in the X and Y directions is adjusted by the XY collector 21 shown in FIG. In doing so, it is positioned at the initial position in the X and Y directions.

The Z stage 12 supports the transmission / reception ferrule 7 and abuts against the multi-core connector 2 to be measured, and is finely movable in the vertical direction orthogonal to the XY stage 10 shown by the arrow Z in FIG. Then, the Z controller 22 shown in FIG.
The vertical movement is controlled by. Here, the transmitting / receiving ferrule 7 is attached to one end of the transmitting / receiving fiber 8, and the other end of the transmitting / receiving fiber 8 is connected to the optical power meter 24 of FIG. As a result, the light-transmitting / receiving ferrule 7 is optically connected to any one of the optical fibers 3 a to 6 by abutting the multi-core connector 2.

The Z controller 22 is connected to the optical connector 2 based on the relationship between the transmission loss of the measuring light and the end face distance measured in advance between the reference connector having the same structure as the optical connector 2 to be measured and the transmitting / receiving ferrule 7. The position of the Z stage 12 is adjusted so that the light transmitting / receiving ferrule 7 is abutted at a preset desired interval. That is, the XY stage 1
The reference connector is attached to the mounting hole 10a of No. 0, and the transmitting / receiving ferrule 7 supported by the Z stage 12 is butted to the reference connector. Then, with the core centers of both optical fibers 3a and 8 aligned, the Z-axis stage 12 is moved in the vertical direction, the transmission loss L is measured at each moving position, and the transmission loss L and the end face spacing shown in FIG. Create a correlation diagram for Z. On the basis of this correlation diagram, in the measurement regarding the multi-core connector 2, the Z controller 22 controls the vertical position of the Z stage 12, and the transmission loss is L ₀ when the end surface distance Z between the multi-core connector 2 and the light-receiving and ferrule 7 is controlled. It is maintained at a preset desired end face spacing Z ₀ .

Here, the end surface spacing Z ₀ is defined as the optical fiber 3a attached to the multicore connector 2 to be measured.
Is slightly inclined with respect to the abutting direction, the measurement error due to this inclination is negligible.
Set to about m. The Z scale 13 is the Z stage 12
In the laser sensor for measuring the fine movement position in the vertical direction indicated by the arrow Z, the vertical position is adjusted by the Z collector 23 shown in FIG.

The optical power meter 24 includes a transmitting / receiving fiber 8
The light intensity of the measurement light transmitted from the light source 4 is measured, and an optical signal corresponding to the measured light intensity is output to the computer 14 shown in FIG. The computer 14 operates the Z controller 22 based on the optical signal input from the optical power meter 24 according to a preset program so that the distance between the end faces is Z _0, and the multi-core connector 2 that maximizes the intensity of the measurement light. The position of the core center of each optical fiber 3a and the inspection fiber 6 of each inspection ferrule 5 is calculated.

Then, the XY controller 20, XY
Collector 21, Z controller 22, Z collector 23,
As shown in FIG. 2, the optical power meter 24 and the light source 4 are connected to the computer 14 and their operations are controlled.
The dimension measurement of the optical connector of the present invention is performed as follows using the dimension measurement system 1 described above.

First, in each pin hole 2c of the multi-core connector 2,
The inspection ferrule 5 is inserted so as to be substantially flush with the butt end surface 2b. Next, the multi-core connector 2 is attached to the XY stage 1.
The first optical fiber selected from a total of six optical fibers including the optical fiber 3a and the inspection fiber 6 to be measured by the light transmitting / receiving ferrule 8 of the light transmitting / receiving ferrule 7 while mounting the Z stage 12 in the mounting hole 10a of 0. Butt with the multi-core connector 2 so as to be optically connected to. At this time, the Z controller 22 adjusts the position of the Z stage 12 so that the end surface distance Z between the optical connector 2 and the light transmitting / receiving ferrule 7 becomes a desired end surface distance Z ₀ set in advance.

When the Z stage 12 is moved up and down, the computer 14 controls the operation of the Z controller 22 as follows. That is, computer 1
4 calculates the end surface distance Z between the multi-fiber connector 2 and the light-transmitting / receiving ferrule 7 based on the optical signal input from the optical power meter 24. Based on this end face distance Z, the computer 14 outputs a correction signal to the Z controller 22 to finely move the Z stage 12 to move the end face distance Z.
Correct the difference ΔZ from ₀ . As a result, the transmitting / receiving ferrule 7 can be prevented from coming into contact with the butt end face 2b of the multi-core connector 2.

Next, the optical power meter 24 measures the light intensity of the measuring light transmitted through the light transmitting / receiving fiber 8. At the time of this measurement, the XY stage 10 is moved in the X and Y directions within the range of the optical fiber optically connected to the inspection fiber 6, and the transmission loss L of the measurement light is the smallest, and the measurement is performed by the optical power meter 24. The computer 14 calculates the position of the core center of the optical fiber at which the light intensity of the measured light is maximized.

Similarly, the transmitting and receiving ferrules 7 are sequentially switched to the second to sixth optical fibers of the plurality of optical fibers 3a and the inspection fiber 6, and the position of each optical fiber 3a, 6 is calculated by the computer 14. Ask for. As a result, in the multi-core connector 2, the positions of the plurality of optical fibers 3a based on the pin hole 2c with respect to either one are obtained, and the dimension measurement is completed.

As described above, in the direction of the present invention, when measuring the dimensions of the optical connector based on the correlation between the end face distances of the optical connector and the inspection ferrule and the transmission loss, which have been measured in advance, the optical connector to be measured and the optical connector to be inspected are measured. Maintains a constant distance from the ferrule. For this reason, the transmission loss caused by other than the distance between the end faces of the optical connector to be measured and the transmission / reception ferrule is removed, and the measurement accuracy in the dimension measurement of the optical connector is improved.

Incidentally, in measuring the dimensions of the multi-core connector 2, it goes without saying that, contrary to the above embodiment, the light transmitting / receiving fiber 8 may be connected to the light source 4 and the tape fiber 3 may be connected to the optical power meter 24. Nor. Further, the optical connector may be a single-core connector as well as a multi-core connector.

[0025]

As is apparent from the above description, in the method for measuring the dimensions of the optical connector of the present invention, the end face spacing in the abutting direction when the optical connector serving as a reference and the sending / receiving ferrule are abutted is changed. While measuring the transmission loss and measuring the correlation between the end face spacing and the transmission loss, the end face spacing in the abutting direction with the light emitting and receiving ferrules is held at a constant interval based on the correlation, and the measurement target Since the dimension of the optical connector is measured, the dimension of the optical connector can be measured with high accuracy.

[Brief description of drawings]

FIG. 1 is a perspective view showing the configuration of a dimension measuring system for measuring the dimension of an optical connector by the method of the present invention.

FIG. 2 is a schematic connection diagram showing a schematic connection state of the dimension measuring system shown in FIG.

FIG. 3 is a correlation diagram showing a correlation between an end face distance and a transmission loss in a reference optical connector.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Dimension measurement system 2 Multi-core connector 3 Tape fiber 3a Optical fiber 4 Light source 5 Inspection ferrule 6 Inspection fiber 7 Transmitting / receiving ferrule 8 Transmitting / receiving fiber 10 XY stage 11 XY scale 12 Z stage 13 Z scale 14 Computer (ECU) )

Claims (1)

[Claims] 1. A transmission / reception ferrule to which an optical fiber is attached and at least one optical fiber is attached, and an optical connector to be measured is butt-connected and transmitted from either one side of the transmission / reception ferrule or the optical connector. In the dimension measuring method of the optical connector, in which the measured measurement light is measured on the other side and the dimension of the optical connector is measured based on the measurement result, when the reference optical connector and the transmitting / receiving ferrule are butted. While measuring the transmission loss while changing the end face spacing in the butt direction, and measuring the correlation between the end face spacing and the transmission loss in advance, when measuring the dimensions of the optical connector to be measured based on the correlation, A method for measuring the dimensions of an optical connector, characterized in that the distance between the end faces in the abutting direction with the light transmitting / receiving ferrule is maintained at a desired distance. Law.